I also agree! :D As you probably might know, Norwegian is a Germanic language. Endre is from the German word "ändern", while Forandre is from Low German "voranderen". In the Hanseatic days, (Hansatiden) Norwegians did a lot trade with the Germans and Low German was widely used, this has influenced the Norwegian vocabulary. In fact, more than 30% of the Norwegian everyday speech is originally Low German. Sometimes "endre" collocate better with other words than "forandre", e.g. "Endre seg til det bedre" is more used than "Forandre seg til det bedre", both phrases are fine and correct. But how can you tell which one is most used? Well there is a clever way to figure this out..... :D

Norsk er mitt morsmål. Jeg kan ikke se at det er noen forskjell mellom disse ordene. Begge er vanlige og brukes ofte.